It is well known that tracking customer satisfaction is an important technique for sustained competitive advantage.
More recently customers are using online tools to express their opinions about a wide range of products and services. Many such online tools can be described as being under the general category of “Social Media” (or SM). Online tools in this category include, but are not limited to, the following:                FACEBOOK, Inc. (Menlo Park, Calif., U.S.A.)        TWITTER, Inc. (San Francisco, Calif., U.S.A.)        all variety of “web logs” or “blogs”        all variety of “Web 2.0” sites, that facilitate feedback from a site's audience or readers        
The availability of such SM content raises the question of whether, with appropriate technology, tools can be applied to identify and analyze changes in consumer opinion over time, as expressed in such data.